Abstract:A two-stroke braking turbocharged diesel engine model was established with GT -POWER, and the effects of pressure wave in the intake and exhaust pipes and the turbocharger on the engine intake and exhaust process were considered. The relations between engine speeds and exhaust valve open time and the engine brake performance were studied through simulating the engine two-stroke brake process. The simulation results show that the brake torque and the brake power increase as the engine speed rises when the exhaust valve operation parameters are constant. If the exhaust valve lilt profiles and the second open time are constant, as for every engine speed, the brake power reaches maximum only at the first open time for exhaust valves, and the only open time varies with engine speed. If the exhaust valve lift profiles and the first open time are fixed, the compressor operation points get closer and even beyond the surge line, because of the delay of the second open